The nature of many academic and professional writings is such that authors rely upon and cite previously published works, studies, or test results to support arguments or opinions. For example, in the common law system in America, lawyers and judges cite and rely upon previously decided cases (i.e., written judicial opinions) to support their arguments and opinions. The American common law system is particularly reliant upon the precedent established by previous case decisions because a judicial court (or judge) will usually consider as very persuasive a previously-decided case in which the same legal issue has been resolved or decided.
However, courts will not always agree with, or be bound by, previously-decided cases. Instead of agreeing with a conclusion reached in a previous case, or "following" it, courts may occasionally, disagree with, criticize, question, reverse, or overrule the previous case. Therefore, beginning with the first time a case is cited in a subsequent case, the earlier case's authoritative value can change. For example, if a persuasive judge is critical of the earlier case, that earlier case will be less authoritative than it was before the judge's critical treatment of the case. On the other hand, if the judge strongly supports the reasoning of the earlier case, the authoritative value of the earlier case will be enhanced. Virtually every time a case is discussed or cited, its authoritativeness or precedential status is affected. The importance or precedential status of a case can continue to evolve over many years as a result of interpretations given to it by judges in subsequent cases.
Therefore, when considering a legal issue decided in a court's written opinion or decision, it is critical to consider what subsequent cases have said about it. Lawyers performing legal research consequently have a need to determine which later cases have discussed (and therefore, cited) in any given earlier case. For many years, lawyers have been able to find out which later cases have cited any given case by using a tool known as Shepard's Citations published by McGraw-Hill, Inc. Shepard's Citations is basically an organized index that lists all the cases that have cited a particular case. When a later case cites an earlier case, there is usually some discussion of the earlier, cited case. Shepard's Citations also sometimes gives a brief indication of how the later case treated the earlier case of interest (e.g., the later case may have "followed," "criticized," or "questioned" the earlier case).
In recent years, legal research has been increasingly performed by lawyers using computerized legal research systems. The most popular of these may be the on-line legal research systems, such as Westlaw and LEXIS/NEXIS. However, legal research systems employing local CD-ROM or other databases have become quite popular.
FIG. 1a is a representation of a screen taken from the Westlaw legal research system operated by the West Publishing Company. The screen shows a portion of the text of the Wilson Sporting Goods case shown at 101 in FIG. 1a. The title bar 102 includes the citations 103 for the Wilson case, which are 904 F.2d 677, and 14 U.S.P.Q.2d 1942. These two citations mean that the Wilson case can be found starting at page 677 of volume 904 of the F.2d reporter series, or alternatively, starting at page 1942 of volume 14 of the U.S.P.Q.2d reporter series.
Also shown in the title bar 102 is the "rank" 104 of the displayed document, which is simply the position or order of the Wilson case with respect to all of the other documents found in the search conducted by the user. In this particular example, the Wilson case is ranked second out of three search documents. Each of the search documents is a document that satisfies a particular query entered by the user, and in the example shown in FIG. 1a, three documents in the database CTA satisfy the user's query.
The current page number and the number of pages in the document are shown in FIG. 1a at 105. The number of pages essentially corresponds to the number of screens the Wilson case fills. For example, FIG. 1a shows the first Westlaw page of the Wilson case, and FIG. 1b shows Westlaw page 25. FIG. 1b is the screen that is twenty-fifth of the thirty-nine screens that make up the Wilson case. FIGS. 1a and 1b thus simply show different portions of the text of the Wilson case.
As described above, when researching issues that are discussed in the Wilson case, it is very useful to see what subsequently decided cases have said about the analysis in the Wilson case. The Westlaw system provides access to this type of information through a number of services, one of which is the on-line version of Shepard's Citations. In the Westlaw system, the user can access this information by selecting a menu item from a pull-down menu or by selecting (i.e., "clicking on") an on-screen button. When the user selects the Shepard's Citation service in Westlaw while viewing the Wilson case, a screen similar to that shown in FIG. 1c is displayed.
The top of FIG. 1c shows at 110 a citation to the cited document, 904 F.2d 677, which is the citation to the Wilson case. Thus, the Wilson case is considered, in this screen, to be the "cited" document. A parallel citation to the Wilson case is shown at 114. FIG. 1c also contains a list 112 of citations to a number of cases. The citations in this list 112 are references to cases which cite the Wilson case. These cases listed at 112 are called "citing cases" because they are later cases that cite the Wilson case (i.e., the cited case). In other words, the text of each of the cases shown in the list 112 contains a specific reference to the Wilson case.
The citation 116 at the bottom of FIG. 1c ("140 F.R.D. 121, 127"), indicates that a case having a citation to the Wilson case can be found starting at page 121 of volume 140 of the F.R.D. (Federal Rules Decisions) reporter series. The specific citation or reference to the Wilson case can be found on page 127 of that volume. FIG. 1c also shows at 118 that this citation references headnote 9 of the Wilson case. This means that the case at 140 F.R.D. 121 cites the Wilson case for the issue discussed at headnote 9 of the Wilson case. The headnotes are prepared and categorized by the West Publishing Company.
As suggested at 120 of FIG. 1c, the Shepard's listing for the Wilson case spans eight Westlaw screens. Page 2 of the Shepard's listing is shown in FIG. 1d. This page lists additional citing cases (i.e., cases that cite the Wilson case). As can be seen from FIGS. 1c and 1d, the Shepard's citations are listed in a somewhat organized manner. For example, in FIG. 1d, the cases decided in the First Circuit that cite the Wilson case are listed under the heading "Cir. 1, " and the cases in the Second Circuit that cite the Wilson case are listed under heading "Cir. 2."
FIG. 1d also shows an instance in which the Shepard's listing analyzes one of the listed citations. At 122, the Shepard's listing suggests that the case published at 796 F.Supp. 640 (the "citing case") "followed" the analysis or reasoning of the Wilson case. This means that the citing case (found at 796 F.Supp. 640) applied the same analysis as the court in the Wilson case. The Shepard's Citations listing also will occasionally provide other analysis of citing cases, and may, for example, point out those cases which "explain," "criticize," or "reverse" the Wilson case.
As described above, the Westlaw system allows the researcher to see a list of citing cases, such as that provided by Shepard's Citations. However, the Westlaw system requires the user to move to another screen to see these citations, thereby covering the displayed text of the case of interest. This is distracting to the researcher, because once the text of the case is no longer displayed, the researcher cannot refer back to the displayed text without removing the citations from the screen. In addition, because the citations list in Westlaw can often be many screens in length, the user must perform the tedious task of paging through the entire citations list and uncovering those citations that are relevant to the particular portion of the displayed document that the researcher is studying. The Westlaw system and others in the art are therefore relatively unsophisticated in the manner in which they display lists of citing cases. None of the computer-based research systems in the art provide a listing of citing cases which is based on the context of the displayed document. Thus, none provide any indication of which citing cases specifically refer to the text displayed on the screen or selected by the user.